From the picture below, what is the measure of CD ?

Answer:
[tex]\frac{r}{2} \pi[/tex]
Step-by-step explanation:
CD equals 1/4 of the total circumference ([tex]2r\pi[/tex]), which is [tex]\frac{r\pi }{2}[/tex].
Is anything defined on this picture? For example:
[tex]r = \frac{CE}{2} = \frac{DG}{2} = CH = DH = GH = EH ...[/tex]